1. Field
The present disclosure relates to a composition, in particular a composition comprising a microencapsulated component. The composition finds particular use in the formulation of volatile components and is generally applicable, for example, to formulating agrochemical active ingredients. The present disclosure further relates to a method of preparing the same and, still further, to the use thereof.
2. Description of Related Art
Emulsifiable concentrate (EC) agricultural formulations of pesticides are well known in the art. These formulations are generally prepared by emulsifying and dispersing agents in addition to the pesticide to give a uniform composition. However, these agricultural formulations suffer numerous drawbacks because they are liquid. In particular, liquid pesticidal formulations must be handled carefully to minimize safety concerns, in particular dermal and ocular irritation. U.S. Pat. No. 6,387,388 contains a discussion of the drawbacks of such liquid formulations.
It is known in the art to microencapsulate pesticidal active compounds in a shell of polyurea. Unfortunately, these formulations do not provide optimum herbicidal efficacy when compared to the corresponding commercially available emulsifiable concentrate formulations. Many studies have shown that, in practice, the release rate of the active ingredient from the microcapsules is directly linked to the efficacy of the formulation in the field. It is well known in the art that the release rate of the active ingredient from the microcapsules is controlled by such factors as microcapsule size, degree of cross-linking, choice of polymer type, wall thickness and mobility of the oil phase.
U.S. Pat. No. 4,285,720 discloses a process for the production of microcapsules. The techniques disclosed provide for the production of microcapsules which are unimodal in terms of wall thicknesses, and size. However, if microcapsules of differing modalities are desired, an entirely separate reaction would have to be conducted. It would be advantageous to provide microcapsules of differing dimensions and wall thicknesses.
U.S. Pat. No. 6,380,133 discloses a technique to encapsulate clomazone in polymer shell, with the polymer shell incorporating cross-linking of the polymer chains. However, control of the release rate of clomazone is still not satisfactory. An improved formulation for encapsulating volatile components, such as clomazone, is therefore needed.